in buf_page_set_sticky

commit a1f899a8 (MDEV-23233) added the
code to make page sticky. So that InnoDB can't allow the page to
be grabbed by other thread while doing lazy drop of ahi.

But the block could be in flush list and it could have io_fix value
as BUF_IO_WRITE. It could lead to the failure in buf_page_set_sticky().

buf_page_create(): If btr_search_drop_page_hash_index() must be invoked,
take x-latch on the block. If the block io_fix value is other than
BUF_IO_NONE, release the buffer pool mutex and page hash lock and
wait for I/O to complete.